Saturday, November 14, 2015

What is tapa cloth?

Tapa cloth is an unwoven kind of bark cloth made by soaking and pounding the soft inner bark of the paper mulberry and certain other trees.  It is the traditional fabric of Polynesia.  Tapa cloth was once widely used for clothing and mats on the islands of the South Pacific.

While modern woven cloth has replaced the traditional native tapa cloth, it is still manufactured on such islands as Tonga and Fiji for special ceremonial occasions.

To make tapa cloth, the tapa maker carefully peels off the white inner layer of mulberry bark and soaks it in water.  The water-soaked bark is then pounded on a log with a wooden club until the narrow strips widen into the proper width and thickness. 

By pasting overlapping edges with glue made from plant roots, the tapa maker fashions sheets of larger sizes.  The tapa cloth is then decorated with dyes made from plant juice.– Dick Rogers

Tuesday, November 10, 2015

What is a timberline?

Some mountains have trees growing clear to their tops, but on many high mountains there is a line above which trees stop growing.

The place where trees stop growing is called the “timberline”.  Trees don’t grow above it because they cannot survive the freezing temperatures there.

Above the timberline the mountainside is likely to be a cold desert with only patches of lichens, moss and stunted vegetation twisted by the strong winds of the mountain tops.
Here, the bitter cold keeps the water in the ground frozen for much of the year, and bigger plants cannot get enough water.

Just  below the timberline the tall pine forests stand alone.  There tough, needle-shaped leaves can withstand the icy winds and harsh living conditions on the cold mountainside better than the broad-leaf trees can.

The timberline is much higher on some mountains than on others.  It depends on the climate, and latitude.

Friday, November 6, 2015

What is the Statue of Liberty made of?

The Statue of Liberty is one of the United States’ most famous monument. This colossal statue of a robed lady with a torch in her raised right hand and carrying a tablet in her left, stands on Liberty Island in New York Harbor.  It is made of more than 300 copper sheets over a steel and iron framework. 

It was designed in 1881 by a French sculptor, Frederic Auguste Bartholdi, and was presented to the people of the United States as a gift from the people of France.  Working from a model only 49 inches high, Bartholdi worked up a full-sized wood and plaster model which was divided into sections. 

Next, thin copper sheets were hammered over the wooden molds and shaped to their contours.  The copper shells were then bolted to the central framework.  The statue was taken apart from shipment from France and reassembled in the United  States.  Even though it is hollow, the statue weighs 225 tons.  It is 151 feet tall. – Dick Rogers


Monday, November 2, 2015

How was the grand canyon formed?

One of the great natural wonders of the world is Arizona’s Grand Canyon of the Colorado River.  The whole gorge is 217 miles long and, from rim to rim, 4 to 18 miles wide.

One of the most amazing things about it is that it was made by a river!  Almost hidden between the canyon walls a mile below, the rushing waters of the Colorado River, with the help of many smaller rivers flowing into it, carved out this great chasm in the course of millions of years.

Even now, the ceaseless cutting continues to carve deeper into the canyon floor.  Erosion from wind and rain have increased the size of the ever-widening, many-colored rock formations that resemble a fairyland of towering peaks and castles.

Color change with the shifting shadows and the changing light.  The Grand Canyon became a national park in 1919. – Dick Rogers

Thursday, October 29, 2015

Why was the Eiffel tower built?

The Eiffel Tower is a huge tower in Paris, France.  It was built for the Paris Universal Exhibition (a world’s fair), held in that city in 1889.

The tower, named for its designer, Alexander Eiffel, was intended to be the symbol and main attraction of the fair, just as most world’s fairs have one structure to symbolize the particular fair.

When the fair ended, the tower was left standing.  Today it is the most famous landmark of the French capital.

The tower rises 984 feet in the air and contains 7,000 tons of iron and steel.  At the time it was built, it was taller than anything else anyone had ever built.  Now the Empire State Building is nearly 300 feet higher than the Eiffel Tower.

If you take an elevator to the top, you can see all over Paris.  You will also find a restaurant in the tower, as well as a weather station.  There is a tall TV antenna on top that sends programs al over the city. – Dick Rogers

Sunday, October 25, 2015

Why do sunsets look red?

During the evening, when the sun is near the horizon we may see a beautiful sunset.  The reds and oranges of a sunset are caused by the filtering action of the sky.

Sunlight, as we know, is made of many colors.  We can see the colors that make up sunlight when we look at a rainbow.  As sunlight passes through the atmosphere, the different colors are scattered by the air.

During the day, when the sun is directly overhead, its rays do not have to travel through as much of the atmosphere to reach the earth.  The sunlight is scattered in such a way that we see more of the blue rays.  But at sunset, when the sun is low in the sky, the light rays must travel through much more of the earth’s atmosphere to reach the viewer.

As a result, the shorter blue rays are soon scattered out and we can see more of the longer orange and red rays of sunlight – and we have a reddish sunset.  The red color of sunrise is caused the same way. – Dick Rogers

Wednesday, October 21, 2015

How are rocks made?

Rocks are found almost everywhere.  Very small rocks are called sand.  Rocks bigger than sand have other names, like pebbles, or stone.  Big rocks are called boulders.  In fact, almost all the earth – the mountains and the ground itself – is made of rock.

Rocks are made of minerals.  A few are made of just one mineral, but most rocks are made of many minerals, of magma, that lies under the earth’s crust.  As the magma pushes to the surface of the earth.  It cools and hardens into such rocks as granite, basalt and lava.

Some rocks are formed from bits and pieces of older rocks that pile up in layers and harden into rocks we know as sandstone and limestone.  Still other rocks began as one kind of rock and later were changed into other kinds of rocks.  Some limestone, for example, was changed by hear and pressure deep down in the earth into marble.

Saturday, October 17, 2015

What makes a waterfall?

On its way to the sea, a river or stream may plunge over a steep cliff.  If it does, there is a waterfalls in mountains than anywhere else.  Many waterfalls were caused when ancient glaciers of earthquakes created a sharp-edged cliff in the path of a stream or river.  

Often, waterfalls are caused as the river carves away at the riverbed as it flows downstream.  Over the years, a softer place in the riverbed wears down and becomes a steep cliff.

Giant waterfalls are called cater acts.  Where the water does not drop straight down, but rushes down steep slopes instead, it is called a cascades.  If a riverbed slopes even less steeply, it is often called a rapids.  

As far as anyone knows, the highest waterfalls in the world is Angel Falls in Venezuela.  It is a silvery ribbon of falling water that plunges over 3,000 feet down the face of a cliff. – Dick Rogers

Tuesday, October 13, 2015

How does a blimp stay in the air?

A blimp is an airtight bag that is able to rise in the air because it is filled with light gases.  A blimp is a small, balloon-like airship.  Unlike the heavier-than-air airplane, the blimp remains aloft because it is lighter than air.  

It needs only small motors to push it forward.  Blimps are descendants of the simple balloon. The blimp's lift comes from a lighter-than air gas that raises the blimp in the same way a balloon is lifted.

A balloon rises because the gas inside the balloon is much lighter than the air round it, and so it floats in the atmosphere, in much the same way a ship floats on water.  The gas inside the blimp expands and fills out the blimp.  Its gasbag has no framework inside, and collapses when the gas is taken out.

Some airships, such as the dirigible, have an inside framework that supports the sides, and do not depend on the pressure of the lifting gas to maintain their shape.  During World War II, blimps protected ships by spotting enemy submarines.  

They were also used for observation, photographing enemy positions and for rescues at sea and on land.  Today, blimps with signs painted on their sides are used mostly for advertising and sightseeing. – Dick Rogers

Friday, October 9, 2015

What were the Egyptian pyramids built for?

The Egyptian pyramids were built as tombs for ancient Egyptian kings.  Perhaps the first thing you would look for if you visited the United Arab Republic would be the ancient Egyptian pyramids near the Nile river.  

Each pyramid was build as a tomb to protect the body of an Egyptian king.  The Egyptian thought that a man’s body had to be protected and preserved so his soul could live forever.
When a king died, the people “mummified” (dried and wrapped) his body and buried it in a secret chamber deep inside an enormous pyramid, built of stone blocks to last a long time.  

It was built large to tell the world how great the king was.  Many treasures of gold and precious objects were buried with the king so that his spirit could enjoy them. Food and other necessities wee also put in the pyramid for the king in his future life.  

After the king’s mummy was placed in the pyramid, the inner passages were blocked. It took millions of stones to build a big pyramid.  Many of the blocks weighed more than a ton apiece.  A big pyramid meant the work of thousands of slaves for many years. – Dick Rogers

Monday, October 5, 2015

What causes thunder?

Thunder occurs when a flash of lightning heats the air in its path.  The heated air expands, for wing a sound wave which we hear as thunder.  What makes the loud clap of thunder that often follows a flash of lightning?  

Lightning is a big electrical spark.  During a thunderstorm, electrical charges are built up in the clouds.  If the charges become great enough, a flash of lightning occurs. As the lightning bolt jumps across the sky, it quickly heats the air in its path.  

The flash comes from a hot glowing gas in the lightning channel.  The heated air quickly expands outward as violently as if there had been an explosion.  This causes a great wave of air (or sound wave) which we hear as thunder.

Each part of the zigzag bolt causes an air wave, so you often hear, thunder as a short, sharp clap followed by a series of rumbles set up by the part of the lightning bold that is farthest away.  Thunder crackles when lightning forks out into many branches.  It takes about five seconds for the sound of thunder to travel one mile. – Dick Rogers

Thursday, October 1, 2015

How Did Badminton Get Its Name?

Badminton is a game somewhat like tennis, because in both games an object is hit over a net with rackets.  But the badminton racket is lighter than a tennis racket and a feathered shuttlecock, or “bird,” is hit instead of a tennis ball.

Badminton is a present-day version of an earlier and simpler game called “battledore and shuttlecock,” which was first played several hundred years ago in India and other Eastern countries.

A group of Englishmen brought it to England. It was played so much at a place in England called Badminton that it was named after this place.

The object of the game is to bat the shuttlecock from one player to the other without allowing it to fall to the ground or bounce as a tennis ball does.

A badminton shuttlecock is often called a “bird” because it has real feathers tied to a piece of cork.The feathers guide the shuttlecock when you hit it over the net.


The “bird” often used in badminton today has a plastic crown, instead of the old feather crown.Dick Rogers

Friday, September 18, 2015

What are stars made of?

Stars
Stars are formed from gigantic masses of hot glowing gases.  Hydrogen and helium are the most common gases in a star.  In the clearest night sky you might see a few thousand stars with unaided eye.  Every bright star is a sun, like our own sun.
Scientists tell us that a star is a huge glowing ball of hot gases.  It is a kind of gigantic atomic furnace in which the temperature at the center may be as high as several million degrees.  Hydrogen and helium are the most common gases found in a star.  Although they are made up of gases, their centers are so dense and hot that the atoms of gas are constantly colliding and fusing together into new materials.
As the atoms unite, some of their atomic energy is given off  in the form of heat and light which stream away from the star in all directions.  This is why stars shine.  Scientists can find out all this by using instruments called spectroscopes.  With these instruments they can tell from the light a star gives what the star is made of and how hot it is. – Dick Rogers

Sunday, September 6, 2015

How did death valley get its name?

Death Valley
Death valley was named in 1849 but the survivors of a party of prospectors, many of whom died of heat and thirst while looking for gold in the valley.  The hottest, driest and lowest place in the United States is Death Valley.  Death Valley is a desert basin that lies mostly in Southern California.
Death Valley is about 140 miles long and 4 to 16 miles wide.  About 500 square miles of the valley are below sea level, including the lowest spot in North America (282 feet below sea lever near Bad Water).

Only about two inches of rain fall on Death Valley’s wastelands each year and the scorching heat has reached 134 degree in the shade—a record high temperature in the United States.  Despite the burning hear many kinds of plants thrive here, such as mesquite and desert holly.  You can find coyotes, rabbits, rattlesnakes, birds and many other creatures living here, too. – Dick Rogers


Thursday, September 3, 2015

Why Is A Desert Dry?

Deserts cover nearly a fifth of the earth’s surface.  We would probably describe a desert as a hot, barren land where it hardly ever rains—a land so dry that few plants can grow on it, and where other
Dry Desert
forms of life also find it difficult to exits.  The desert we have just described occupies nearly a fifth of the earth’s land surface.  Large deserts can be found in all of the continents except Europe.
The driest and hottest deserts are found in the trade wind zones north and south of the Equator.  Deserts in these areas, such as the Sahara Desert of North Africa, are dry even though they may be near the ocean waters.  Here the winds blow across the desert toward the Equator and become very hot and dry, and release little of their moisture as rain.
Some deserts are dry because they are so far from the sea that the winds blowing in from the ocean lose their moisture long before they reach these deserts.  And in many cases, desert regions are cut off from the moisture laden sea air by tall mountains that catch the rainfall on their seaward side. – Dick Rogers